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(No Model.) 5 Sheets-Sheet 1.

' L. UHLER.

A STEAM S UPERHEATER WITHIN DEPENDENT FURNACE.

No. 510,658. A Patented Dec. 12-, 1893.

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STEAM SUPERHEATER WITH INDEPENDENT FURNACE.

No. 510,658. Patented Dec. 12,1893.-

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(No Model.) 5 Sheets-Sheet 3.

L. UHLER. STEAM SUPERHEATER WITH INDEPENDENT FURNACE. No. 510,658.

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Patented Dec. 12, 1893.

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L.UHLER. STEAM SUPERHEATER WITH INDEPENDENT FURNACE.

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UNITED STATES PATENT 0FFICE- LOUIS UHLER, or GENEVA, SWITZERLAND, ASSIGNOR TO LOUIS UHLER & CADISCH, oF sAME PLACE.

STEAM-S UPE RH EAT R WITH INDEPENDENT FURNACE.

SPECIFICATION formingpart r Letters r c nt No. 510,658, dated December 12, 1893.

Application filed October 22, 1892. Serial No. 449,636. (No model.) Patented in France February '11, 1892, No. 219,306; in

- $witzerland March 19, 1892, No. 4,851, and in Italy April 23, 1892, XXVI,S1,616, LXII, 138.

T0 at whom it mag concern.-

Be it known that I, LOUIS UHLER, a citize of Switzerland, residing at Geneva, Switzerland, have invented certain new and useful Improvements in Steam-Superheaters with Independent Furnaces, of which the following is a specification. Q

The presentinvention has been patented in foreign countries, as follows: in France No. 219,306, dated February 11, 1892; in Switzerland No. 4,851, dated March 19, 1892, and in Italy XXVI, 31,616, LXII, 138, dated April 23, 1892.

In constructing vertical steam superheat-' ers with independent furnaces various inconveniences have shown themselves, and the present invention has for its object an improved construction of such superheaters whereby the said inconveniences are obviated. Experience has shown that the vertical superheater requires the tubes to be placed at least 2.40 meters away from the fire, in order to prevent their too rapid deterioration. As the tubes themselves are 2.40 meters high, it follows that the upper part of thetubes is4.80 meters from the fire; at this distance the temperature of the combustion gases is hardly as high as that of the superheated steam, and in addition, the transmission of heat takes place very imperfectly between gases when they ascend vertically in contact with vertical tube surfaces. In consequence hereof it has been Q necessary to construct such superheaters with I a relatively very great extent of heating surface, thereby greatly increasing the cost thereof. In addition the great total height of such superheaters (being about 'six meters) frequently causes great inconvenience and difficulty in properly locating them, and furthermore, the lower ends of the vertical tubes where they are formed with joints are the parts subject to the greatest heat and are consequently most liable to deterioration, as the joints being brazed, are liable to give way under excessive heating.

According to the present invention, these disadvantages are obviated by arranging the tubes of the superheater horizontally; also, by.. the introduction of tubes not connected with thesuperheaterbetween the superheatertubes I and the fire, we are enabled to bring the said tubes nearer to the furnace, so that as the bottom tubes are considerably lower than in the case of vertical tubes, they are subjected to a much'higher temperature, thus effecting a'better utilization of the furnace heat, and consequently enabling the heating surface to be considerably reduced. By this means the height of the superheater, its cost of installation, and the quantity of fuel required for 6 heating it, are all reduced to a corresponding extent.

On the accompanying drawings is shown a superheater constructed according to my said invention. v

Figure 1 shows a longitudinal section. Fig. 2 is a front view and Fig. 3 is a cross section. Fig. 1 is a horizontal section on line XXFig. 1. Fig. 5 is a horizontal section through the front part of the superheater. Fig. 6 is a horizontal section on line Y Y Fig. 3. Fig. 7 is an enlarged detail view. Figs. 8 and 9 are sections on lines Z Z and W W of Fig. 7, and Fig. 10 is another enlarged detail view.

In the arrangement here shown, the. tubes of the superheater are constructed in a similar manner to Field boiler tubes placed horizontally the concentric tubes 0. I), being adapted to one or more boxes K (two in the present case) each being divided by a partition 0 into two compartments, of which one,

P communicates with the internal tubes 12,

while the other R communicates with theouter tubes a, the steam to be superheated being introduced into the compartment P and con- 8: sequentlyforced to pass first through the inner-tubes b,'and then back again through the annular space between a and 19, becoming superheated on its way, and then through the chamber R.

The furnace A is of ordinary construction, either with intermittent or continuous firing, and the boxes or chambers K with their tubes 01, b, are suitably supported above it. The waste combustion gases escape through a de- 5 scending pipe B Fig. 1, communicating with the flue of the steam boilers, or they may be led into a sheet iron chimney 0' indicated in dotted lines in Figs. 1 and 2. The furnace D passing away and casing of the superheater are built of ordinary brickwork strengthened by iron stays E, Figs. 2 and 5. The furnace chamber is lined 'with fire bricks, which can be readily renewed.

The superheating tubes are supported at their closed ends, which arenot fixed to boxes K, by means of two tiers of movable cast iron supports H H placed closely side by side, which supports are of a width equal to the distance from center to center of the tubes, and can be removed at will for the passage of instruments for the withdrawal and replacing of tubes when required. The tubes are supported at the middle of their length by means of a tubular metal bearer 1 Figs. 1 and 3, and by movable struts K K Figs. 1 and 10, which are pushed into their place from the front, before placing the supports II in position. It will be seen that the ar rangement is such that one or more defective tubes can be removed without requiring the operator to enter the furnace, as was requisite with the vertical arrangement of the tubes, necessitating the stoppage for a long time of the superheaters action, in order to allow the furnace to cool down. The front side of the furnace is partly closed by a sheet iron door L and partly by brickwork O. The tubular bearer 1 has air admitted to it at P Fig. 3 and it communicates at the other end with a passage R formed in the brickwork, opening underneath the furnace grate. This arrangement has for its object both to keep the bearer cool and to supply hot air to the furnace. I11 the roof of the tube chamber are formed openings S S Figs. 1 and 4, the number and area of which are calculated to give a suitable direction of the hot combustion gases, in order that the tubes may be more or less uniformly heated thereby.

An important feature of the improved superheater consistsin the employment of tubes T '1" that are not connected to the superheater, and the object of which is to preserve the lower rows of superheating tubes from excessive heating.

Experiments have shown that, in a group of superheated horizontal tubes, only the three lower rows can become red hot by excessive heating. Consequently by the application of three rows of protective tubes T all excessive heating and oxidation of the superheating tubes will be avoided, and these will therefore be much more durable. The tubes T can be of any description. They are supported on the one hand by the casting H which, together with the brickwork m also supports the boxes K of the superheater tubes, and on the other hand they are supported by movable supports H of cast iron, the construction of which is shown at Figs. 7, 8 and 9. These movable supports are secured in such manner as not to allow the entrance of air between them. The movable supports 1-1 are held at bottom by a bearer s secured so as to be removable. The two upper sets of movable supports 11 H are held in the same manner by a bearer s.

The tubes '1" can be rapidly removed and replaced from the outside without stopping the working of the superheater. Cold air enters them from one end so as to cool them to a certain extent and also to provide a further supply of hot air which passes from the other end of the tubes into flues N N and enters the furnace above the fire through nozzles U U for the purpose of consuming the smoke.

The fire-brick arch V which is built below the tubular bearer I can be readily reconstructed when worn out; it serves to protect the bearerI against excessive heat from the fire.

When a superheater with independent fire is used in combination with boilers worked at a high pressure, there will frequently be carried, along with the steam, Water charged with solid impurities,owing to priming. These solid impurities would be precipitatedto the lower sides of the superheating tubes and would accumulate therein so as to eventually prevent the circulation of the steam through the tubes, so that these, being no longer in contact with steam, would rapidly burn away. For the purpose of preventing such solid impurities from passing into these tubes, there is placed at any convenient point between the steam boilers and the superheater a water and mud separator, or purifier, consisting of a recipient K provided with two branch pipes 7a separated by a partition 70? provided with pendent tubes 70 it, so that the steamentering through the branch k will first pass downward with considerable velocity through the tubes 70 on its way to the branch Ichandthe solid impurities will consequently be precipitated from the steam to the bottom ofthe receptacle K This is provided witha mud cock G at bottom, through which the accumulated impurities can be discharged from time to time. The tubes T might of course be replaced by solid iron bars, of about the same diameter as the tubes. These tubes T or the bars replacing the same, may also be applied with advantage to steam superheaters placed in the furnaces or fines of steam boilers.

Having now particularly described and ascertained the nature of my said invention and in what mannerthe same is to be performed, I declare that What I claim is- 1. A superheater for steam, having its superheating tubes arranged in a substantially horizontal position over the furnace and a series of hollow bars arranged between the lower tier of superheating tubes and the fire pot, the said hollow bars communicating at one end with the outer air and at the other end with a fine or lines leading to the furnace, substantially as set forth.

2. In a superheater for steam, the combination with a set of superheating tubes arranged over a furnace, the said furnace, and an arch, V, spanning the furnace below the tubes, of a tubular, metal bearer, I, extending across the furnace and resting on said arch, and movable supports for the middle portion of the series of superheating tubes, resting on said bearer I, as set forth.

3. In a superheater for steam, the combination with the series of superposed tiers of tubes, of movable supports H- for the closed ends of said tubes, said'supports being upright and having a width equal to the space between centers of two adjacent vertical rows of tubes, whereby said supports distance and space the tubes and form a close wall, as shown.

4. In a superheater for steam, the combination with a furnace and a series of superheating tubes arranged over the same, of a series of tubular bars T, arranged under the superheating tubes and over the furnace, and a tubular metal bearer 1, arranged under the tubes T and across the furnace, said bars T,

and bearer I, communicating at one end with the outer air and at the other end with fiues leading to the furnace, whereby a draft is created through the same, as set forth.

5. In a superheater for steam, the combination with the series of superposed tiers of tubes supported at their ends, as shown, of the tubular metal bearer I, and the removable'iutermediate supports, K, arranged between the tubes, having their ends curved or hollowed, as shown, to fit the rounded surfaces of the tubes, as set forth. a

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

LOUIS UHLER.

Witnesses:

Louis 0. TETARD, G. C. WELKER. 

